Difficulty of entitling a subclass corresponding to every combination.
This superorder is equivalent to the subclass Azygostei of Hay.
This subclass, like the previous one, contains only a single order, viz.
This subclass contains some of the most remarkable of the seaweeds.
There remains the fourth subclass—Dipnoi or Dipneusti, the lungfishes.
Embryo with a pair of ...